Piston-packing for steam-engines.



0'. H. POLLARD.

PISTON PACKING FOR STEAM ENGINES,

APPLICATION PILED JULY 20, 1912.

Patented May. 4, 1913.

Guam

warmom is through the passages against the inner faeesand centers or,the;

STATES PAE I F'ENT OFFICE.

CHARLES H. POLLARII), or OAKDALE, TENNESSEE.

PISTON-PACKING FOR STEAM-ENGINES.

To an unto m itmay concern @Be it known that I, UHAnLi-as H. PoLLARo,

a citizen of the United States, residing at Oakdale, in the county ofMorgan and State of 'lt-innessee, have invented new and usefulImprovements in Piston-Packing for Steam-' injuring the wall of thecylinder, and at the same time avoiding the formation of vacuums in theopposite ends of the cylinders, which serve to retard the free back andforth movement of the piston, when not erforming its work under steampressure.

Withthe above and other objects in view, the invention consists in theconstruction, combination, and arrangement of parts, as will behereinafter more fully described,

illustrated in the accompanying drawings,

and pointed outv in the claim hereunto appended. v

In the drawingsr Figure .1 is an end view of a piston embodying thepresent invention. Fi 2 is a plan or face view, looking toward teperiphery thereof. Fig. 3 is a diametrical-section through the piston.Fig. t'is a. detail perspective view of one of the piston rings.

Referring to the drawings, 1 designates a piston'of any desired size andgeneral dimensions, the same being shown as provided witha plurality ofgrooves 2 to receive the pistmi-nngs 3, each of which is of the usualform in cross section, being shown as substantially square.

4 designates the piston rod.

In carrying out the present invention, a number of steam inlet passages5 are formed in the op osite ends of the piston, said passages lea inginto the bottoms of the grooves 2, and opening up therein aboutcentrally of thetra'hsverse dimensions of said groov as so. that thesteam pressure passing-inner Specification of Letters Patent.

Application filed J'uly20, 1912. Serial No. 710.632.

be expanded in size and I111l11-' 5 W'lll. be dir ctgd Patented Ma r. 419113.

piston rings 3. Any desired number of said passages 5 may be employed inaccordance with the size of the piston and other conditions. 1

Each piston ring is formed as shown in Fig. 4, and in the preferredembodiment ot the invention, each piston ring comprises three sections6, 7 and 8. The sections 6 and 7 are divided transversely, as shown at8, and the meeting faces of said sections are counter-bored, as shown at9, adapting them to fit together on opposite sides of a pin 10 whichextends across the groove in which the ring is received, and such pin isfastened to the piston, so that when the sect-ions (J and 7 are inengagement with said pin, the piston ring as a whole is prevented fromturning around within its groove. By' roviding the packing rin sectionswith t e split abutting ends, as shown at the bottom of Fig. 4-, andforming said abutting ends with halt-round grooves which register witheach other and form together a round opening, and by inserting a pin inthe opening which fills the same, the sections are held in properalinement with each other at all times, and the pin inserted in saidhole serves as a brake joint or stop, preventing the leakage of steam orother expansive fluid at such point. This makes the packing ring at suchpoint practically pressure-proo The section 8 of the piston ring isconnected with the sections 6 and 7 by miter or oblique joints, asindicated at 11, thereby forming what may be termed a lap joint whichwill not have any tendency to score the wall of the cylinder in the backand forth movements of the piston rings. Furthermore, this allows thering toexpand and contract, without permitting the steam to pass by thesame. i

By means of the construction hereinabove described, the packing rings ofa steam engine will last several times as long as the ordinary packingrings now in common use, for the reason that the wear thereon ismaterially reduced, in view of the fact that when the steam is cut offin a locomotive engine, for example, when the locomotive is driftingdown a grade, the iston rings will ride loosely against the wa ls of thecylinders, and relieve the friction thereof, and also prevent theformation of a partial vacuum in the opposite ends of the cylinders,this resulting in allowing a much freer drifting,

sol-coasting of the engine down grade. w

also results in a mziterial reduction'of e1;- pense in the lip-keep ofthe engine, and en-' ables the same to be run for a much greater periodof time, Without repair. "Furthermore, th'e' construction described willprevent the bursting of cylinder 'headsend other damage caused by theaccumulation of water in the cylinder, and will adlnit of easylubrication. 1

What is claimed is:

A pistonformed in its periphery with a in presence of sections having ahip joint at one piece and a joint at another place formed by providingthe sections with square abutting ends having registering half-roundgrooves therein midway between the outer and inner feces oil. the ringand extending parallel to the axis of the piston, and a pin passingthrough'said'grooves and acting as a stop or closure for said joint,said pin. being car riedby the piston.

In testimony whereof I aim my signature of two witnesses. CHARLES- H.PQLLARD. Witnesses W. Y. BoswELL,

R, J. W LKm.

